My touring gears consist of : 22-34-46 chainrings, 12-32 8 speed cassette, MTB derailleurs (very old XTR, they were the previous year's model when I bought them), and downtube-mounted friction shifters (yes, they can still be found) with no indexing option. The ultra-low gearing is very nice when hauling camping gear in steep terrain, especially as the day goes on and one gets tired.. Friction shifting eliminates the shifting problems that can arise when cables get kinked, housings crack or get dirt in them, or when various drivetrain parts start to wear. Putting the shifters on the downtube keeps them out of the way when loading the bike onto airplanes, trains and ferries, and eliminates the extra cables that can get in the way of a handlebar bag. The 8 speed cassette gives me all the gears I need, and I think it's a little more durable than a 9, 10 or 11 speed cassette.